We know,
![D=RT](https://img.qammunity.org/2023/formulas/mathematics/college/cgvntvbsmdlgndt0acy832tszzuxnaj20y.png)
Where
D is the distance
R is the rate
T is the time
United Airlines Flight A
D = 2000 miles
T = 5 hours
So,
![\begin{gathered} D=RT \\ R=(D)/(T) \\ R=(2000)/(5) \\ R=400mi\/hr \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/vdxrxa08ro7biqnms0re3ba9pqxc3jn6as.png)
United Airlines Flight B
D = 2000 miles
T = 4 hours
So,
![\begin{gathered} D=RT \\ R=(D)/(T) \\ R=(2000)/(4) \\ R=500mi\/hr \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/d317n9mmit1itj0grozln043gnnnad5f16.png)
Now,
When Flight B has flown 1500 miles, 1500/500 = 3 hours have passed.
Flight A started 1 hour earlier than Flight B, so 3 + 1 = 4 hours have passed until Flight B has flown 1500 miles.
Thus,
Flight A traveled 400 miles/hr * 4 = 1600 miles in those 4 hours
How far ahead is flight A than flight B????
1600 miles - 1500 miles = 100 miles
Answer100 miles